I made basil pesto the other day and used way too much salt. (By the way, "pesto" means "paste" in Italian; arugula, parsley and basil are just some of the greens which can be used to make pesto.) It was almost inedible.
I wasn't about to throw it out, though, and wondered how I could salvage it. Adding more basil would do the trick, but I didn't have any left. Instead, I decided to use Dinosaur kale. I added a handful of the kale leaves to the food processor, which contained the too-salty paste of basil, garlic, toasted walnuts, Parmigiano-Reggiano, salt (did I mention I used too much?), fresh ground pepper and olive oil.
The extra greens did the trick. The pesto didn't have the basil punch I wanted, but at least I had something—basil-kale pesto—to show for my efforts.
The moral of the story? Most of the time, there are ways to correct cooking screw-ups and you don't have to be Julia Child or Albert Einstein to figure things out.